The present invention relates generally to trailer hitches and, more particularly, to a trailer hitch which automatically locks on a hitch ball when the hitch ball is placed within the socket of a coupler, to prevent unintentional dislocation of the ball from the socket as the trailer is being pulled.
Automatic trailer hitch locks are known in the art. These mechanisms generally operate through the use of a friction cam or similar device which wedges against a portion of the housing of a coupler as a socket is placed over a hitch ball. This friction lock mechanism reduces the chance of the hitch ball inadvertently becoming dislodged from the coupler during transport of a trailer. An example of such a device is shown in U.S. Pat. No. 4,239,252, wherein a two-piece socket, having a fixed forward piece and a rear piece which pivots from a ball release position to a ball engagement position. The rear piece is disposed toward the ball engagement position by a spring or similar resilient means. To place a ball within the two-piece socket, a handle or similar mechanism must be lifted to move the rear unit into a ball receiving position before the ball is inserted into the two-piece socket. As the ball is placed within the two-piece socket, the rear unit "automatically" moves into the ball receiving position and a cam, or similar friction mechanism, locks the rear unit in the ball securing position. This automatic locking action prevents the ball from becoming inadvertently dislodged from the two-piece socket as the trailer is being pulled.
Generally, the friction lock alone is not safe for transport of a trailer. A handle or similar mechanism typically must be manually depressed after the automatic friction lock has been engaged to positively secure the socket around the ball. The trailer then may be transported without fear of the friction lock mechanism accidentally becoming dislodged during transport.
Although such mechanisms are generally adequate for receiving and securing a hitch ball within a socket, they are often complicated and cumbersome to use. The handle must be kept elevated as the socket is placed over the ball, leaving a user with only a single arm to lift and maneuver the trailer hitch onto the ball. Furthermore, if the user forgets to positively secure the handle in the downward locked position, only a friction connection means between a cam and the hitch housing prevents the socket from becoming inadvertently dislodged from the hitch ball during transport.
The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.